Trial device for testing a size of a spinal disc space

ABSTRACT

A spinal fusion system may include an interbody fusion cage, a fixation plate, and an implanter. The interbody fusion cage may include a proximal region, a distal region opposite the proximal region, a superior region, an inferior region opposite the superior region, and an open volume between the proximal and distal regions. The superior and inferior regions are located between the proximal and distal regions and are configured such that, when the interbody fusion cage is implanted in the disc space, the superior region contacts the inferior end plate and the inferior region contacts the superior end plate. the fixation plate is receivable in the open volume of the interbody fusion cage and includes a superior blade and an inferior blade. At least one of the blades includes a first opening defined therein. The fixation plate is displaceable between a non-deployed state and a deployed state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/928,799, entitled “STAND-ALONE CAGE SYSTEM: INTEGRATEDANCHOR/SCREW DESIGN,” filed on Jan. 17, 2014; 61/949,015, entitled“SYSTEM AND METHOD OF IMPLANTING A SPINAL IMPLANT,” filed on Mar. 6,2014; and 61/969,695 entitled “SPINAL FUSION SYSTEM,” filed Mar. 24,2014. The full disclosures of the above-listed patent applications arehereby incorporated by reference herein.

FIELD

Aspects of the present disclosure relate to systems and methods for thetreatment of spinal conditions. More specifically, the presentdisclosure relates to spinal implants and delivery systems for, andmethods of, delivering and implanting spinal implants in a spinal columnin the treatment of a spinal condition, including spinal fusiontreatments.

BACKGROUND

Spinal fusions are commonly performed on patients suffering from painand dysfunction stemming from spinal trauma, degenerative diseases,birth defects, etc. Spinal fusions can be time intensive to perform, andsurgical outcomes for patients are not always as desired or hoped for.

There exists a need in the art for improved spinal fusion systems andmethods.

BRIEF SUMMARY

Disclosed herein is a spinal fusion system and method for fusingtogether a superior vertebra and an inferior vertebra. The superiorvertebra includes an inferior endplate and a vertebral body, and theinferior vertebra includes a superior endplate and a vertebral body. Thesuperior and inferior endplates define a disc space.

In one embodiment, the spinal fusion system includes an interbody fusioncage, a fixation plate, and an implanter. The interbody fusion cageincludes a proximal region, a distal region opposite the proximalregion, a superior region, an inferior region opposite the superiorregion, and an open volume between the proximal and distal regions. Thesuperior and inferior regions are located between the proximal anddistal regions and are configured such that, when the interbody fusioncage is implanted in the disc space, the superior region contacts theinferior end plate, and the inferior region contacts the superior endplate. The fixation plate is receivable in the open volume of theinterbody fusion cage and includes a superior blade and an inferiorblade. At least one of the blades includes a first opening definedtherein. The fixation plate is displaceable between a non-deployed stateand a deployed state, wherein, when the fixation plate is received inthe open volume and the fixation plate is in the non-deployed state, thesuperior and inferior blades extend generally parallel to each other.And, when the fixation plate is received in the open volume and thefixation plate is in the deployed state, the superior and inferiorblades extend oppositely from each other.

The implanter includes a distal end configured for releasable couplingwith the proximal region of the interbody fusion cage. The implanterfurther includes a first guide system configured to guide a firstdelivery trajectory of a first bone screw. The first delivery trajectoryincludes a first axis that extends along the first guide system andthrough the first opening when the distal end is coupled to the proximalend and the blades are in the deployed state.

In one embodiment, the superior and inferior blades in a deployed statemay extend generally perpendicular to a direction the blades extendedwhen in a non-deployed state. In another embodiment, the superior andinferior blades may extend generally parallel to each other, pointingproximally and being substantially within the open volume.

In another embodiment, the superior blade includes the first opening,and the inferior blade includes a second opening. Further, the implanterincludes a second guide system that is configured to guide a seconddelivery trajectory of a second bone screw. The second deliverytrajectory includes a second axis that extends along the second guidesystem and through the second opening when the distal end is coupled tothe proximal end and the blades are in the deployed state.

In another embodiment, the first guide system includes a distalcomponent and a proximal component proximally offset from the distalcomponent. Each component acts to at least partially confine the firstaxis of the first delivery trajectory to pass through the first openingwhen the distal end is coupled to the proximal end and the blades are inthe deployed state. This embodiment may also include where the distalcomponent restricts the first delivery trajectory in four directionsalong two axes perpendicular to the first axis. This embodiment mayadditionally include where the proximal component restricts the firstdelivery trajectory in three directions along two axes perpendicular tothe first axis.

Moreover, this embodiment may also include where the distal componentincludes a fully enclosed opening in a structure near the distal end,and the implanter further includes a proximal handle comprising a grooveextending longitudinally along the handle, the groove comprising theproximal component.

In another embodiment, the system further includes a screw driver. Thescrew driver includes a distal end adapted to mechanically engage adistal end of the first screw. Additionally, the screw driver is furtheradapted to interact with the first guide system in delivering the firstscrew through the first opening along the first trajectory.

In another embodiment, the fixation plate includes a drive mechanismthat drives the fixation plate from the non-deployed state to thedeployed state. Additionally, the implanter further includes a drivecomponent that interacts with the drive mechanism to cause the drivemechanism to drive the fixation plate. In this version, the drivemechanism may include a drive nut threadably supported on a threadeddrive shaft, the drive nut being coupled to the fixation plate. And, thedrive component may include a member rotatable to the implanter andincluding a distal end that engages the threaded drive shaft to transmitrotation of the member to the threaded drive shaft. This version mayalso include where the drive nut proximally displacing along thethreaded drive shaft causes the fixation plate to transition from thenon-deployed state to the deployed state.

In another embodiment, the implanter includes a ramp distally projectingfrom the distal end of the implanter. The blades abut against slopedsurfaces of the ramp, where the abutting causing the blades to divertfrom the non-deployed state to the deployed state.

In another embodiment, the distal end includes distally projectingmembers that are received in the proximal region of the interbody fusioncage to couple the case to the distal end in a releasable manner. Inthis embodiment, the projecting members may include at least one ofsmooth pins for an interference fit, threaded pins for a threadedengagement, or hook-latches for a hooked engagement.

In another embodiment, the proximal region of the interbody fusion cageincludes an open configuration through which the fixation plate can bedelivered.

In another embodiment, the interbody fusion cage and the fixation plateare configured to interact with each other when the fixation plate islocated in the open volume and in the deployed state such that thefixation plate and interbody fusion cage become locked together toprevent anterior-posterior and lateral displacement relative to eachother. In this version, the interbody fusion cage may include a slot ornotch that receives a portion of one of the blades when the fixationplate is located in the open volume and in the deployed state.

Also disclosed herein is a method of fusing a superior vertebra to aninferior vertebra. In one embodiment, the method includes inserting aninterbody fusion cage into a disc space defined by an inferior endplateof the superior vertebra and a superior endplate of the inferiorvertebra (step a). The method further includes causing an inferior bladeof a fixation plate located in an open volume of the interbody fusioncage to penetrate the superior endplate and extend at least half avertical distance of a vertebral body of the inferior vertebra into thevertebral body of the interior vertebrae (step b). The method furtherincludes causing a superior blade of the fixation plate to penetrate theinferior endplate and extend at least half a vertical distance of avertebral body of the superior vertebra into the vertebral body of thesuperior vertebra (step c). The method also includes causing a firstbone screw to penetrate an anterior face of the vertebral body of theinferior vertebra and extend into the vertebral body of the inferiorvertebra to be received in an opening defined in the inferior bladeembedded in the vertebral body of the inferior vertebra (step d). Themethod also includes causing a second bone screw to penetrate ananterior face of the vertebral body of the superior vertebra and extendinto the vertebral body of the superior vertebra to be received in anopening defined in the superior blade embedded in the vertebral body ofthe superior vertebra (step c).

In one embodiment, steps d) and e) are brought about via a blinddelivery of the bone screws via an implanter coupled to a proximalregion of the interbody fusion cage. In this version, the implanter mayinclude inferior and superior trajectory guides that respectively haveinferior and superior axes that respectively extend through the openingdefined in the inferior blade and the opening in the superior blade whenthe blades are embedded in the respective vertebral bodies.

While multiple embodiments are disclosed herein, the various embodimentsas described in this disclosure are capable of modifications in variousaspects, all without departing from the spirit and scope of the presentdisclosure. Accordingly, the drawings and detailed description are to beregarded as illustrative in nature and not restrictive.

These and other aspects and embodiments will be described in furtherdetail below, in reference to the attached drawing figures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a proximal isometric view of a spinal fusion system with thespinal implant supported on a distal end of the implanter, the anteriorfixation plate deployed, and the screw driver interfaced with theimplanter, so as to be properly aligned to guide the first of two bonescrews through corresponding receiving openings of the plate, accordingto one embodiment;

FIG. 2 is a longitudinal side elevation of the spinal fusion system andrelationships depicted in FIG. 1;

FIG. 3 is a longitudinal top plan view of the spinal fusion system andrelationships depicted in FIG. 1;

FIG. 4 is a longitudinal bottom plan view of the spinal fusion systemand relationships depicted in FIG. 1;

FIG. 5 is a distal end elevation of the spinal fusion system andrelationships depicted in FIG. 1;

FIG. 6 is a proximal end elevation of the spinal fusion system andrelationships depicted in FIG. 1;

FIG. 7 is an enlarged distal isometric view of the distal end of thespinal fusion system of FIG. 1, showing the spinal implant supported onthe distal end of the implanter, with the anterior fixation plate in anon-deployed state, such that the fixation plate is substantially, ifnot entirely, located within the confines of the exterior boundaries ofthe interbody fusion cage;

FIG. 8 is the same enlarged distal isometric view of FIG. 7, except theanterior fixation plate is in a deployed state, such that the fixationplate extends so as to project substantially past the confines of theexterior boundaries of the interbody fusion cage, so as to be capable ofpenetrating the end plates of the immediately adjacent vertebrae andthereby extend into the bodies of said vertebrae.

FIG. 9 illustrates the same aspects as FIG. 8, except in an enlargedproximal isometric view;

FIG. 10 is an enlarged distal isometric view of the distal end of thespinal fusion system of FIG. 1, showing the spinal implant supported onthe distal end of the implanter, with the anterior fixation plate in adeployed state and a bone screw received through an opening in theinferior blade of the fixation plate;

FIG. 11 is a distal isometric view of a screwdriver of an implantationset, according to one embodiment;

FIG. 12 is a distal isometric view of an implanter of an implantationset, according to one embodiment;

FIG. 13 is a longitudinal cross-sectional view of the implanter of FIG.12, as taken along section line 13-13 of FIG. 12;

FIG. 14 is a lateral or transverse cross section of the implanter, astaken along section lines 13-13 in FIG. 1;

FIG. 15 is an enlarged distal isometric view of the implanter distalend, wherein a deployment ramp extends distally from the distal face ofthe cage interface of the implanter;

FIG. 16 is a distal isometric view of the deployment ramp depicted inFIG. 15;

FIG. 17 is a proximal isometric view of the deployment ramp;

FIG. 18 is a superior plan view of the deployment ramp, the superiorplan view being identical to what would be an inferior plan view;

FIG. 19 is a lateral side elevation of the deployment ramp, thedeployment ramp having the identical appearance if view from an oppositeside of the ramp;

FIG. 20 is a distal elevation of the deployment ramp;

FIG. 21 is a proximal elevation of the deployment ramp;

FIG. 22 is a proximal isometric view of an anterior fixation plate in anon-deployed state, according to one embodiment;

FIG. 23 is a distal isometric view of the anterior fixation plate in thenon-deployed state;

FIG. 24 is a proximal isometric view of the anterior fixation plate in adeployed state;

FIG. 25 is a distal isometric view of the anterior fixation plate in adeployed state;

FIG. 26 is a lateral side elevation of the fixation plate threadablyengaged with the threaded distal termination of the implanter in thenon-deployed state, according to one embodiment;

FIG. 27 is the same view as FIG. 26, except the fixation plate is in thedeployed state;

FIG. 28 is a proximal isometric view of the interaction of the plate andramp when the plate is in the non-deployed state of FIG. 26;

FIG. 29 is a lateral side elevation of the interaction of the plate andramp when the plate is in the non-deployed state of FIG. 26;

FIG. 30 is a proximal isometric view of the interaction of the plate andramp when the plate is in the deployed state of FIG. 27;

FIG. 31 is a lateral side elevation of the interaction of the plate andramp when the plate is in the deployed state of FIG. 27;

FIG. 32 is a proximal isometric view of an interbody fusion cage,according to one embodiment;

FIG. 33 is a distal isometric view of the interbody fusion cage;

FIG. 34 is a superior plan view of the cage, the inferior plan viewbeing identical to the superior plan view;

FIG. 35 is a longitudinal cross section of the cage in a proximalisometric view, as taken along section line 35-35 in FIG. 32;

FIG. 36 is a lateral cross section of the cage in plan view, as takenalong section line 36-36 in FIG. 33;

FIG. 37 is the same lateral cross section of the cage as in FIG. 36,except shown in distal isometric view;

FIG. 38 is an enlarged distal isometric view of one of the extremelateral wings of a plate blade being received in the space defined bythe pair of inward projections of a side wall of the cage, according toone embodiment;

FIG. 39 is generally the same cross section view as illustrated in FIG.35, except showing the plate and drive nut in the non-deployed statewithin the cage;

FIG. 40 is an enlarged plan view cross section of the entire distalregion of the system, as taken along section line 40-40 in FIG. 1;

FIG. 41 is a proximal isometric view of an interbody fusion cage,according to an alternative embodiment;

FIG. 42 is a proximal cross section of the distal region of the system,as taken along section line 42-42 in FIG. 41;

FIG. 43 is a proximal isometric view of the system adjacent a superiorvertebra and an inferior vertebra;

FIG. 44 is a vertical cross section through the two vertebrae with thefixation plate in the deployed state;

FIG. 45 is a proximal isometric view of the bone screws being implanted;

FIG. 46 is a proximal isometric view of the finished implantation of theimplant with the vertebrae shown in phantom;

FIGS. 47A-47C are perspective, top and perspective views, respectively,of a trial implant device with rotating cutting blades, according to oneembodiment;

FIGS. 47D and 47E are perspective views of a system and method for usingthe trial implant device of FIGS. 47A-47C, according to one embodiment;

FIGS. 48A and 48B are cross-sectional, end-on views of a trial implantdevice with linear cutting blades, according to an alternativeembodiment;

FIGS. 49A and 49B are perspective and exploded views, respectively, ofan interbody fusion cage with anchoring plates, according to anotherembodiment;

FIG. 49C illustrates a method for inserting an anchoring plate into aninterbody cage, according to one embodiment; and

FIGS. 50A-50C are side view of a device for implanting the interbodyfusion cage and anchoring plates of FIGS. 49A-49C.

Corresponding reference characters and labels indicate correspondingelements among the views of the drawings. The headings used in thefigures should not be interpreted to limit the scope of the claims.

DETAILED DESCRIPTION

Referring to FIG. 1, in one embodiment, a spinal fusion system 6 mayinclude a spinal implant 8 and an implantation tool set 10 fordelivering and implanting spinal implants in a spinal column to treat aspinal condition. In one embodiment, the spinal implant 8 includes aninterbody fusion cage 12, an anterior fixation plate 14, and bone screws16 that are received by the fixation plate. The implantation tool set 10includes an implanter 18 and a screw driver 20.

The cage 12 is designed to be implanted in a disc space between asuperior vertebra and an inferior vertebra and to act as a fusion cagesystem to fix and fuse the superior and inferior vertebrae together. Thecage 14 is delivered to the disc space via the implanter 18. Whenimplanted in the disc space, the cage 12 abuts against the superiorplate of the inferior vertebra and the inferior plate of the superiorvertebra

The plate 14 includes a superior blade 22 and an inferior blade 24. Theplate 14 is designed to be located within the boundaries of the cage 12and delivered into the disc space with the cage 12 via the implanter 18.When located both within the boundaries of the cage 12 and the confinesof the disc space, the plate 14 is deployed via action of the implanter18 to penetrate from the disc space into the superior and inferiorvertebrae, thereby spanning the two vertebral sections bordering thedisc space in which the cage is implanted and preventing the cage fromdisplacing in an anterior-posterior direction or a medial-lateraldirection. When the plate 14 is deployed to extend into the superior andinferior vertebrae, the superior blade 22 and the inferior blade 24,respectively, extend superiorly and inferiorly from the boundaries ofthe cage 12 to respectively penetrate the superior and inferiorvertebrae.

The implanter 18 is configured to deliver the fusion cage 12 and thefixation plate 14 positioned within the boundaries of the cage 12 intothe disc space. Upon both the cage 12 and plate 14 being implanted inthe disc space, the implanter 18 may be used to cause the plate 14 todeploy such that the plate 14 extends into the superior and inferiorvertebrae. The screw driver 20, which is guided in its displacement andalignment via the implanter 18, is used to deliver a superior bone screw16 through an anterior body face of the superior vertebra such that thesuperior bone screw 16 is received by the superior blade 22. Similarly,the screw driver 20 is used to deliver an inferior bone screw 16 throughan anterior body face of the inferior vertebra such that the inferiorbone screw 16 is received by the inferior blade 24. Once the bone screwsare so received by the plate 14, which extends into the vertebraebordering the disc space in which the cage 12 is implanted, theimplanter 18 may be decoupled from the implanted cage 12, theinteraction of the cage 12, plate 14 and bone screws 16 acting as animplant that fuses the superior and inferior vertebra together.

a) The Spinal Fusion System

To begin a detailed discussion of the spinal fusion system 6, referenceis now made to FIGS. 1-6. FIG. 1 is a proximal isometric view of thespinal fusion system 6 with the spinal implant 8 supported on a distalend 26 of the implanter 18, the anterior fixation plate 14 deployed, andthe screw driver 20 interfaced with the implanter 18, so as to beproperly aligned to guide the first of two bone screws 16 throughcorresponding receiving openings 28 of the plate 14. FIGS. 2-6 are,respectively, a longitudinal side elevation, a longitudinal top planview, a longitudinal bottom plan view, a distal end elevation, and aproximal end elevation of the same system 6 and relationshipsillustrated in FIG. 1. The implantation tool set 10 includes theimplanter 18 and a screw driver 20, and the spinal implant 8 includesthe interbody fusion cage 12, the anterior fixation plate 14 and bonescrews 16. The distal end 26 of the implanter 18 is configured tosupport the interbody fusion cage 12 and the fixation plate 14 as anintegral unit during the implantation of the cage 12 and plate 14 into adisc space located between upper and lower vertebrae defining the discspace. Further, the implanter 18 is used to actuate the fixation plate14 from a non-deployed state (shown in FIG. 7), where the plate 14 issubstantially, if not entirely, located within the confines of theexterior boundaries of the cage 12, to a deployed state (shown in FIGS.8-9), where the plate 14 extends so as to project substantially past theconfines of the exterior boundaries of the cage 12 so as to be capableof penetrating the plates of the immediately adjacent vertebrae andthereby extend into the bodies of said vertebrae.

As indicated in FIGS. 1-6, the screwdriver 20 and the implanter 18 areconfigured to interface in a manner that automatically causes thescrewdriver 20 to distally displace along a superior axis AA that iscoaxial with a superior opening 28 in a superior blade 22 of thedeployed plate 14, such that a superior screw 16 can be driven “blind”through the superior vertebral body to be received in the superioropening 28 in the superior blade 22 projecting into the superiorvertebral body, thereby greatly enhancing the fixation of the superiorblade 22 in the superior vertebral body. Similarly, the screwdriver 20and the implanter 18 are configured to interface in a manner thatautomatically causes the screwdriver 20 to distally displace along aninferior axis BB that is coaxial with an inferior opening 28 in aninferior blade 24 of the deployed plate 14, such that an inferior screw16 can be driven “blind” through the inferior vertebral body to bereceived, as illustrated in FIG. 10, in the inferior opening 28 in theinferior blade 24 projecting into the inferior vertebral body, therebygreatly enhancing the fixation of the inferior blade 24 in the inferiorvertebral body. One of the ways in which the spinal fusion system 6disclosed herein is advantageous is that it facilitates superiorfixation that is easily and quickly achieved, resulting in cost savingsand a better outcome for the patient.

b) The Implantation Tool Set

To begin a discussion of the details of the components of theimplantation tool set 10, reference is made to FIG. 11, which is adistal isometric view of the screwdriver 20. As shown in FIG. 11, thescrewdriver 20 includes a distal end 30, a proximal end 32 opposite thedistal end 30, an elongated shaft 34 that extends between the ends 30,32, a gripping handle 36 on the proximal end of the shaft 34, and ascrew engagement feature 38 defined in the distal end of the shaft 34.The screw engagement feature 38 may be of any male or femaleconfiguration that will allow the screw engagement feature 38 tomechanically engage a proximal region of the bone screw 16, which may bein the form of a screw head, to allow the screwdriver to be used todrive the bone screw 16 into bone tissue.

Turning now to another component of the implantation tool set 10,reference is now made to FIG. 12, which is a distal isometric view ofthe implanter 18. As illustrated in FIG. 12, the implanter 18 includes adistal end 26, a proximal end 42, and an elongated body 44 extendingbetween the distal and proximal ends. As discussed in greater detailbelow, the distal end 26 is configured to engage the interbody fusioncage 12 and deploy the anterior fixation plate 14, a proximal region ofthe elongated body 44 is configured for gripping by a first hand, andthe proximal end 42 is configured for gripping by a second hand inbringing about the deployment of the fixation plate 14.

As depicted in FIG. 13, which is the same view of the implanter 18 ofFIG. 12, except the implanter 18 is shown in a longitudinal crosssection as taken along section line 13-13 in FIG. 12, the implanter 18includes an outer assembly 46 and an inner assembly 48 coaxiallypositioned within the outer assembly 46 and rotationally displaceablewithin the outer assembly 46 about a common longitudinal axis of theouter and inner assemblies 46, 48. As can be understood from FIGS. 12and 13, the outer assembly 46 at the distal end 26 includes a cageinterface 50 adapted for coupling with fusion cage 12 in securing thefusion cage 12 to the distal end 26 of the implanter 18. The cageinterface 50 includes a generally planar distal face 52, a firstprojection 54 distally projecting from the distal face 52, a secondprojection 56 distally projecting from the distal face and laterallyoffset from the first projection 54, a center opening 58 generallycentered between the first and second projections 54, 56, a superiorguide channel or opening 60, and an inferior guide channel or opening62. The respective center axes of the first projection 54, the secondprojection 56, and the center opening 58 are positioned along a singlelateral line with the center opening 58 located half-way between thefirst and second projections 54, 56. The superior guide 60, the inferiorguide 62, and the center opening 58 are positioned along a singlesuperior-inferior line that is perpendicular to the single lateral lineassociated with the projections 54, 56, and the center opening 58located half-way between the superior and inferior guides 60, 62.

As illustrated in FIGS. 1, 2, and 8-10, the superior and inferior guides60, 62 guide the respective bone screws 16 along the respective axes AAand BB as the screwdriver 20 is used to distally drive the screws 16into the openings 28 of the respective superior and inferior blades 22,24 of the deployed fixation plate 14. The projections 54, 56 arereceived in the fusion cage 12 near the extreme lateral boundaries ofthe cage 12.

As indicated in FIGS. 12 and 13, outer assembly 46 further includes anelongated tubular body 64 and a grasping handle 66. The tubular body 64extends proximally from the cage interface 50 and the distal end 26towards a proximal end 68 of the tubular body 64. The grasping handle 66extends about a proximal region of the tubular body 64. The handle 66includes six channels, slots, grooves or other features 70longitudinally extending along the handle 66 and evenlycircumferentially distributed about the handle 66. In some embodiments,the number of grooves 70 may be more or less than six. As illustrated inFIG. 14, which is a lateral or transverse cross section of the implanter18 as taken along section lines 14-14 in FIG. 1, regardless of thenumber of grooves 70 in the handle 66, one groove 70 will be axiallyaligned with the superior guide 60 and one groove 70 will be axiallyaligned with the inferior guide 62. As a result and as can be understoodfrom FIGS. 1-3, the groove 70 guides the screwdriver 20 as thescrewdriver shaft 34 distally displaces along the groove 70 to drive thebone screw 16 through the guide 60, 62 and blade opening 28 with whichscrewdriver 20 and screw 16 are aligned via the groove 70 and applicableguide 60, 62. Thus, the handle grooves 70 in combination with the guides60, 62 interact with the screwdriver 20 to guide the screwdriver distaldisplacement along the applicable axes AA, BB to allow for “blind”delivery of the screws 16 into the openings 28 of the blades 22, 24 ofthe fixation plate 14 that has been deployed in the respective vertebraebordering the disc space occupied by the cage 12 delivered via theimplanter 18.

As depicted in FIGS. 12 and 13, the inner assembly 48 includes athreaded distal termination 72, a proximal T-handle 74 and an elongatedshaft 76 that extends between the T-handle 74 and the threaded distaltermination 72.

The elongated shaft 76 extends longitudinally through, and coaxiallywith, the outer assembly tubular body 64. A proximal portion of theshaft 76 projects proximally from the tubular body 64 to extend into theT-handle 74, and a distal portion of the shaft 76 projects distallythrough the central opening 58 to transition into the threaded distaltermination 72. The elongated shaft 76 is rotationally displaceablewithin the outer assembly tubular body 64 about a common longitudinalaxis of the outer and inner assemblies 46, 48. Thus, the T-handle 74 andgrasping handle 66 can each be gripped, and the T-handle 74 can be usedto cause the inner assembly 48 to rotationally displace within the outerassembly 46 to thread the threaded distal termination 72 in a threadedengagement with a drive nut of the fixation plate 14 to cause thefixation plate to deploy or un-deploy as needed within the confines ofthe cage 12 coupled to the distal end of the outer assembly 46.

In one embodiment, the screw driver 20 and the implanter 18 are separatedevices. In another embodiment, one or more screw drivers 20 and theimplanter 18 may be integrated together to form a single integratedstructure or device.

Turning now to the yet another component of the implantation tool set10, reference is now made to FIG. 15, which is an enlarged distalisometric view of the implanter distal end 26, wherein a deployment ramp80 extends distally from the distal face 52 of the cage interface 50 ofthe implanter 18. As shown in FIG. 15, the deployment ramp 80 abuts upagainst the distal face 52 of the cage interface 50, is positionedbetween the pair of projections 54, 56 and the pair or guides 60, 62,and the elongated shaft 76 distally projects through a center opening 82in the ramp 80 that is axially aligned with the central opening 58 ofthe cage interface 50 of the implanter 18. The ramp 80 spreads theblades 22, 24 of the plate 14 apart into the deployed state depicted inFIGS. 1, 2, 8 and 9 when the threaded distal termination 72 is rotatedso as to draw the plate 14 against the ramp 80, as described in greaterdetail below.

As shown in FIGS. 16-21, which are, respectively, a distal isometricview, a proximal isometric view, a superior plan view, a lateral sideelevation, a distal elevation, and a proximal elevation of thedeployment ramp 80, in one embodiment, the deployment ramp 80 includesthe central opening 82, a distal face 84 from which laterallyspace-apart projections or arms 86 distally project, a generally planarproximal face 88, and lateral notches 90 opening in opposite directionsfrom each other and located between the distal face 84 and the proximalface 88. The central opening 80 extends proximal-distal to daylight inthe two faces 84, 88. The two arms 86 are laterally spaced apart fromeach other evenly on each side of the central opening 82 to define a gap92 through which the threaded distal termination 72 of the elongatedshaft 76 projects, as indicated in FIG. 15. Also, as indicate in FIG.15, the notches 90 are generally axially aligned with the projections54, 56 such that the projections 54, 56 extend through said notches 90.

As depicted in FIGS. 16-20, each arm 86 distally terminates in a distalend face 94 and includes a superior surface 96 and an inferior surface98 opposite the superior surface 96 in a superior-inferior direction,and the arms 86 have generally identical configurations to each other.As best understood from FIG. 19, each said surface 96, 98 includes alevel region 96′, 98′ that is parallel to the level region 96′, 98′opposite the arm 86 in a superior-inferior direction.

Additionally, each said surface 96, 98 also includes a sloped region96″, 98″ that curves oppositely to the sloped region 96″, 98″ oppositethe arm 86 in a superior-inferior direction. As can be understood fromFIGS. 7-9 and discussed more fully below, the ramping or deploymentsurfaces 96, 98 of the deployment ramp 80 are acted against by theinside surfaces of the blades 22, 24 of the fixation plate 14 as theplate 14 is proximally driven against the ramp 80 when the threadeddistal termination 72 threadably draws a threaded drive nut 100 of theplate 14 proximally within the cage 12 and between the arms 86.

c. The Spinal Implant

To begin a discussion of the details of the components of the spinalimplant 8, reference is made to FIGS. 22-25. FIGS. 22-23 are,respectively, a proximal isometric view and a distal isometric view ofthe anterior fixation plate 14 in the non-deployed state. FIGS. 24-25are, respectively, a proximal isometric view and a distal isometric viewof the anterior fixation plate 14 in the deployed state. As shown inFIGS. 22-25, the fixation plate 14 includes a superior blade 22, aninferior blade 24, a proximal side 101, an intermediate or joiningportion 102, a distal side 103, and a threaded drive nut 100. The distalside 103 is opposite the proximal side 101, which faces the implanter 18when coupled to the implanter 18.

In some embodiments, the blades 22, 24 and the intermediate portion 102can be a one-piece, unitary structure formed from a single sheet pieceof biocompatible material such as, e.g., stainless steel, titanium,etc., that is bent or otherwise formed into a one-piece, unitarystructure plate 14. In other embodiments, the blade 14 is amulti-element construction formed of one or more separate sheet piecesof biocompatible material that is joined together via, e.g., any of avariety of welding procedures (e.g., laser, chemical, resistance, cold,etc.) or mechanically fastened together (e.g., crimping, etc.) Thethreaded drive nut 100 may be permanently joined to the intermediateportion 102 via any of the aforementioned methods, or the threaded drivenut 100 may even be an unitary structure with the intermediate portion102 or even the blades 22, 24, depending on the embodiment.

As illustrated in FIGS. 22-25, each blade 22, 24 includes a sharpextreme free edge 106 that has sufficient sharpness and rigidity toallow the blade to penetrate the end plate of an adjacent vertebralbody. Also, each blade 22, 24 includes an opening 28 through which abone screw 16 is received via “blind” delivery of the bone screw whenthe blade 22, 24 extends into the vertebral body, as discussed abovewith respect to FIGS. 1-3 and 8-10. Further, each blade 22, 24 includesa pair of extreme lateral wings 107 that interact with features of thecage 12 as described below to prevent anterior-posterior and lateraldisplacement of the cage 12 and fixation plate 14 when the plate 14 isin the deployed state.

The drive nut 100 includes a threaded hole 104 that is threadablyengaged by the threaded distal termination 72 of the inner assembly 48of the implanter 18, as can be understood from FIG. 8. As illustrated inFIGS. 26 and 27, which are lateral side elevations of the fixation plate14 threadably engaged with the threaded distal termination 72 in thenon-deployed and deployed states, respectively, threading of thethreaded distal termination 72 within the threaded hole 104 of the drivenut 100 in a first direction causes the drive nut 100 to displaceproximally along the length of the threaded distal termination 72,thereby driving the fixation plate 14 proximally. Reversing thethreading direction may cause the drive nut 100 to displace distallyalong the length of the threaded distal termination 72, thereby drivingthe fixation plate 14 distally. Alternatively, reversing the threadingdirection may cause decoupling of the threaded distal termination 72 andthe drive nut 100, thus, decoupling the implanter 18 from the implant 8.

Referring to FIG. 26, in one embodiment, a non-threaded portion 105 ofthe inner assembly 48 of the insertion tool 18 is immediately proximalof the threaded distal termination 72, thereby providing a limit tofurther proximal displacement of the drive nut 100 and, as a result, alimit on further proximal displacement of the plate 14. This limit 105provides a tactile feedback to the user that the plate 14 has deployedcompletely.

The deployment of the fixation plate 14 is illustrated in FIGS. 28-31,wherein FIGS. 28-29 are, respectively, a proximal isometric view and alateral side elevation of the interaction of the plate 14 and ramp 80when the plate 14 is in the non-deployed state of FIG. 26, and FIGS.30-31 are, respectively, a proximal isometric view and a lateral sideelevation of the interaction of the plate 14 and ramp 80 when the plateis in the deployed state of FIG. 27. As indicated in FIGS. 28-31,proximal displacement of the plate 14 causes the inner surfaces of theblades 22, 24 to abut against and ride along the ramp surfaces 96, 98.Accordingly, the sloped regions 96″, 98″ drive the blades 22, 24increasingly outwardly as the drive nut 100, and as a result, the plate14 displaces increasingly proximal until the blade 14 reaches thedeployed state illustrated in FIGS. 24-25, 27, and 30-31.

In one embodiment, the blades 22, 24 may be pre-curved to help them todeploy in a curved path into the vertebral bodies. Also, the plate 14may change shape during deployment, guided by the ramp surfaces 96, 98of the ramp 80, which is part of the implanter 18 of the implant toolset 10. The holes 28 may include physical features to prevent backout ofthe bone screws 16 received therein.

The extreme free ends of the blades 22, 24 that terminate in the sharp,rigid edges 106 may have the tri-tip configuration depicted in FIGS.22-25, where the tri-tip configuration includes a central, flat bladesection at a most proximal end of the plate 14 that is positionedbetween a pair of recessed outer tips. The tri-tip configuration mayalso include semi-circular blade sections positioned between each of therecessed outer tips and the central flat blade section as well as a pairof side edges that extend from the respective sides of the extremelateral wings 107 to the recessed outer tips. In one embodiment, allportions of the tri-tip configuration may be sharp, rigid edges 106being meant to improve their ability to cut into cortical bone. In oneembodiment, the blades 22, 24 and the intermediate portion 102 may be acontiguous titanium sheet bent into shape. In one embodiment, the drivenut 100 is fabricated separately and welded into the contiguous bentplate 14. The fixation plate 14 is configured to span two vertebralsections upon reaching the deployed state.

Turning now to another component of the spinal implant 8, reference isnow made to FIGS. 32 and 33, which are, respectively, a proximalisometric view and a distal isometric view of the interbody fusion cage12. As shown in FIGS. 32 and 33, the cage 12 includes a proximal end120, a distal end 122, an interior open volume 124, and an outer wall126 that defines outer peripheral boundaries of the cage 12 and theinterior open volume 124 and separate the volume 124 from the outerboundaries. The wall 126 is incomplete or open on the proximal end 120of the cage 12 such that the cage 12 has a C-cross section or shape ascan be best understood from FIG. 34, which is a superior plan view ofthe cage 12. Thus, the proximal end 120 of the cage 12 has an opening130 that allows the plate 14 and ramp 80 to be inserted into the openvolume 124 of the cage 12.

As indicated in FIGS. 32-34, the wall 126 includes a distal enclosedsection 132 and a pair of side walls 134. A proximal termination 136 ofeach side wall 134 includes a pin receiving hole 138 that projectsdistally into the interior of each side wall 134 from the proximaltermination 136, as best understood from FIGS. 36 and 37, which are,respectively, lateral cross sections of the cage 12 in plan view anddistal isometric view as taken along section line 36-36 in FIG. 33. Eachhole 138 daylights in an interior surface 142 of the respective sidewall134 to define a pocket or recess 189 in the sidewall 134.

As depicted in FIGS. 32, 36, and 37 and further illustrated in FIG. 35,which is a longitudinal cross section of the cage 12 in a proximalisometric view as taken along section line 35-35 in FIG. 32, the distalwall section 132 includes a rectangular recess 137 defined in an innersurface 139 of the distal wall section 132. As can be understood fromFIG. 39, which is generally the same cross section view as illustratedin FIG. 35, except showing the plate 14 and drive nut 100 in thenon-deployed state within the cage 12, the recess 137 receives theextreme distal ends of the plate 14 and the drive nut 100. Also, as canbe understood from FIG. 40, which is an enlarged plan view cross sectionof the entire distal region of the system 6 as taken along section line40-40 in FIG. 1, the recess 137 can be seen to receive the extremedistal ends of the threaded distal termination 72, the ramp arms 86 andthe plate intermediate portion 102.

As shown in FIGS 32-34, the superior and inferior surfaces of the sidewalls 134 include a series of saw teeth or peaks 140. Also, as indicatedin FIGS. 32-37, the interior surfaces 142 of the side walls 134 includesuperior and inferior paired lock tabs in the form of inward projections143, 144 that define a slot, notch, groove or other type of space 146through which the extreme lateral wings 107 extend when the plate 14 isin the deployed state. This locking arrangement, as best depicted inFIG. 38, which is an enlarged distal isometric view of one of theextreme lateral wings 107 being received in the space 146 defined by thepair of inward projections 143, 144, locks the plate 14 and cage 12together to prevent anterior-posterior and lateral displacement of thecage 12 and fixation plate 14 relative to each other when the plate 14is in the deployed state.

In one embodiment, as can be understood from FIGS. 9, 12 and 13, theprojections 54, 56 extend through the distal end 26 of the implanter 18,in addition to projecting into the pin receiving holes 138 of the cage12. As more clearly depicted in FIG. 40, projections 54, 56 may simplybe received in the corresponding pin receiving holes 138 in aninterference or friction fit arrangement. However, in other embodiments,the projections 54, 56 may be in the form of threaded members 54, 56that are rotated via a rotation force applied to their respectiveproximal ends to thread the threaded members 54, 56 into the pinreceiving holes 138, which have complementary threaded arrangements. Tofacilitate the application of a rotational force to the threaded members54, 56 and their rotation about their respective longitudinal axeswithin the distal end 26 of the implanter 18, only the portions of themembers 54, 56 distal of the implanter distal end 26 would be threaded,the portions of the members 54, 56 within the distal end 26 havingsmooth bearing surfaces in smooth bearing surfaced holes 150, theproximal end of each member 54, 56 having a knob for grasping or afeature that facilitates mechanical engagement via a tool such as, e.g.,a screw driver head, Allen wrench or other type of wrench. After fulldeployment of the implant 8, the members 54, 56 could be reverse rotatedto disengage the members 54, 56 from the cage holes 138 to release theimplanter distal end 26 from the cage 12.

In another embodiment, as depicted in FIGS. 41 and 42, which are,respectively, a proximal isometric view of another embodiment of thecage 12 and a proximal cross section of the distal region of the system6 as taken along section line 42-42 in FIG. 41, the pin retainingarrangement discussed above with respect to members 54, 56 beingreceived in cage holes 138 may be replaced with a hook/window engagementarrangement. For example, as shown in FIG. 41, the cage may have slots160 defined in an interior surface 142 of the sidewalls 134, and theseslots 160 lead to windows 162 extending completely through the sidewalls134. As indicated in FIG. 42, hook-latches 166 extend distally from theimplanter distal end 26 and distally terminate in hook features 168.When the implanter distal end 26 is coupled to the cage proximal end,the hook-latches 166 distally displace along the slots 160 and thenmoved outward until the hook features 168 are received in the windows162. The process is reversed to achieve removal of the hook-latches 166.The hook-latches 166 may have a variety of mechanisms for moving thehook-latches inward and outward. For example, such as scissor-likemechanisms, wedge type mechanisms, etc.

For example, wedge-type components can be advanced axially next to thelatch 166 to push them outward. The latches in this case can bespring-loaded to bias them toward the “retracted” position, so that whenthe wedges are removed the latches 166 will go back to the retractedposition for cage release.

As shown in FIG. 42, the openings 150 in the implanter distal end 26 aresufficiently large to allow the passage of the hook features 168 therethrough and their movement inward and outward to engage or disengagefrom the windows 162. Similarly, the ramp 80 is notched out on itsproximal lateral sides to provide sufficient space for the hook features168 to move inward and outward, as called out in FIG. 42 by arrows A andB.

In one embodiment, the interbody fusion cage 12 is formed ofbiocompatible materials, such as, e.g., PEEK, titanium, stainless steel,etc. In one embodiment, the proximal side of the cage 12 is completelyopen, resulting in a horseshoe shape. In other embodiments, the cage 12is closed such that it is contiguous around its perimeter, although alarge proximal opening may be defined in the perimeter to facilitateloading of the plate 14 and bone growth promoting material into the cage12. In one embodiment, the cage 12 has a lateral width of approximately17 mm, a distal-proximal depth of approximately 14 mm depth, and asuperior-inferior height of approximately 8 mm. In other embodiments,the dimensions of the cage 12 will be greater or smaller. For example,the cage widths may be 12 mm, 14 mm, 17 mm, etc., the cage depths may be12 mm, 14 mm or etc., and the cage heights may be 5 mm, 6 mm, 7 mm, 8mm, 9 mm, 10 mm, 11 mm, or etc. The cage 12 may have 5-7 degrees oflordotic angle and/or an anatomic shape to fit the superior vertebraendplate. Also, in some embodiments, the cage 12 may have configurationwith parallel lateral sides. The cage 12 and the corresponding aspectsof the implanter 18 may be configured to have features that interactwith each other to enhance the attachment of the cage 12 to the distalend 26 of the implanter 18.

In one embodiment, the fixation plate 14 and the cage 12 are separateelements that are fitted or otherwise applied together in a prep oroperating room in a surgical facility or otherwise independentlydeployable from each other. In other embodiments, the fixation plate 14and cage 12 are a single integral unit from the manufacturer so noassembly is required in the field. In other words, the cage 12 andanterior plate 14 may be supplied separately, but pre-assembled prior toinsertion. It is also possible for the cage 12 and plate 14 to bedeployed separately if desired. The interior void region of the cage 12in which the plate 14 is located is additionally adapted for the receiptof bone growth promoting material and forms a closed graft space.

The plate 14 includes a superior blade 22 and an inferior blade 24. Theplate 14 is designed to be located within the boundaries of the cage 12and delivered into the disc space with the cage 12 via the implanter 18.When located both within the boundaries of the cage 12 and the confinesof the disc space, the plate 14 is deployed via action of the implanter18 to penetrate from the disc space into the superior and inferiorvertebra, thereby spanning the two vertebral sections bordering the discspace in which the cage 12 is implanted and preventing the cage 12 fromdisplacing anterior-posterior or medial-lateral. When the plate 14 isdeployed to extend into the superior and inferior vertebra, the superiorblade 22 and the inferior blade 24 respectively extend superior andinferior from the boundaries of the cage 12 to respectively penetratethe superior and inferior vertebra.

In one embodiment, the system 6 may further include a trail/sizer toolincluding a set of trial/sizer instruments. Such instruments mayincorporate a pre-scoring blade to break the vertebral endplate prior toinsertion of the spinal implant 8 into the disc space.

d. Spinal Fusion Methodology Employing Spinal Fusion System

To begin a discussion of the details of the methodology of employing thecomponents of the spinal fusion system 6, reference is made to FIGS.43-46, which are, respectively, a proximal isometric view of the system6 adjacent a superior vertebra 200 and an inferior vertebra 202, avertical cross section through the two vertebra 200, 202 with thefixation plate 14 in the fully deploy state, a proximal isometric viewof the bone screws 16 being implanted, and a proximal isometric view ofthe finished implantation of the implant 8 with the vertebra 200, 202shown in phantom.

Initially, as discussed above with respect to FIGS. 28, 29 and others,the anterior fixation plate 14 is loaded onto the ramp 80 in anon-deployed state. The combined ramp 80 and plate 14 are then coupledto the implanter distal end 18 via the threaded distal termination 72being threaded into the drive nut 100, as discussed above with respectto FIGS. 26 and 40, and further via the pins 54, 56 or latches 166 beingreceived in the cage 12 as respectively depicted in FIGS. 40 and 42. Thesystem 6 is now assembled as depicted in FIGS. 1 and 7.

With the system 6 assembled as depicted in FIGS. 1 and 7, the implant 8is inserted via the implanter distal end 26 into the disc space 206defined between superior and inferior vertebra 200, 202 via an anteriorapproach, as indicated in FIG. 43. The handle 74 is then rotatedrelative to the handle 66 of the implanter 18 to cause the drive nut 100to proximally displace along the threaded distal termination 72 to bringthe plate 14 from the non-deployed state (see FIG. 29) to the deployedstate (see FIG. 31), thereby driving the plate blades 22, 24 deep intotheir respective vertebra 200, 202, as shown in FIG. 44. The bladeopenings 28 are now aligned with the axes AA and 88, which are coaxialwith the distal end guides 60, 62 and the handle guides 70, asillustrated in FIGS. 1, 6, 8, 9, 10, 12, and 14 discussed above. Withthe alignment of the guides 60, 62, 70 and the blade holes 28 generallycoaxial with the axes AA and 88, the bone screws 16 can be delivered“blind” to be received in the blade holes 28 embedded deep in thevertebra 200, 202 as indicated by FIG. 45 and discussed above withrespect to FIGS. 1, 2, 10, and 14. The result of the delivery of thebone screws 16 into the holes 28 of the blades 22, 24 embedded in therespective vertebra 200, 202 can be seen in FIG. 46.

With the implant 8 implanted as depicted in FIG. 46, the implanter 18and ramp 80 can be decoupled from the implanted implant 8 and withdrawnfrom the surgical site. Demineralized bone matrix or other paste-likebone graft material can then be injected into the interior volume 124 ofthe cage 12 via the proximal opening 130 in the cage.

In one embodiment, the spinal fusion system 6 disclosed hereinfacilitates the safe and efficient delivery of a spinal implant 8 into adisc space of a patient via an implantation tool set 6 that allows forthe “blind” delivery of a bone screw 16 through a vertebral body andinto an opening 28 in the blade 22, 24 of a fixation plate 14 locatedwithin the confines of a cage 12, said blade 22, 24 projecting asubstantial distance from the cage 12 into the vertebral body. Further,the spinal implant 8 is such that the fixation plate 14 is firstdeployed after which the bone screws 16 are caused to extend throughboth the vertebral body and the blade 22, 24 extending into saidvertebral body, resulting in a plate-to-bone screw engagement. While thesystem 6 describes using bone screws 16 delivered through a vertebralbody and into an opening 28 in the blade 22, 24 of a fixation plate 14,in certain embodiments, the system may function without delivering thebone screws 16 through the opening 28 in the blade 22, 24 of thefixation plate 14. Both types of systems are contemplated and within thescope of the present disclosure.

Referring now to FIGS. 47A-47E, any embodiment of the spinal fusionsystem 6 and methods described above may optionally also include a trialdevice 300 (or “sizer” or “sizing device”). (Trial device 300 may alsobe provided separately and not as part of a system.) Trial device 300may be used to assess a space between two vertebrae, for example. Insome embodiments, trial device 300 may also include one or more blades306 or other cutting devices, which may be used to cut cortical bone andthus prepare one or more bone surfaces for insertion of an interbodyfusion cage or other implant. In the embodiment illustrated, best seenin FIGS. 47A-47C, trial device 300 includes a body 302 and multiple,circular blades 306, which extend through an opening 304 in body 302.Blades 306 are coupled with an actuator 308, which may be rotated tocause blades 306 to rotate. Body 302 includes two channels 310 a, 310 b,into which prongs of an insertion device 312 may be inserted fordelivery of trial device 300 to a position between two vertebrae. Any ofthe components of trial device 300 may be made of any suitablematerials, such as but not limited to any suitable metals, polymersand/or any of the materials described above.

As illustrated in FIGS. 47D and 47E, a distal end of insertion device312 may be coupled with trial device 300 and used to advance trialdevice 312 into a position between a superior vertebra V1 and aninferior vertebra V2. Insertion device 312 may include a handle 316 andan actuator knob 314, the latter of which may extend distally to a bladeactuator, which fits within actuator 308 of trial device 300. Thus,after insertion of trial device 300 between the two vertebrae V1, V2, asshown in FIG. 47D, knob 314 may be turned, as illustrated in FIG. 47E,to actuate blades 306 and thus cut cortical bone of the vertebrae V1,V2. Thus, trial device 300 may serve two purposes—to test a size for apotential interbody fusion cage implant and to prepare one or more bonesurfaces for receiving the implant. In alternative embodiments, trialdevice 300 may not include blades 306 and thus may simply be configuredfor sizing.

With reference now to FIGS. 48A and 48B, in an alternative embodiment, atrial device 320 may include linear-travel blades 322, rather than therotating blades 306 of the previously described embodiment.Linear-travel blades 322 may be driven by an actuator 324, which whenactivated causes blades 322 to move up and down. Actuator 324 may be adrive gear, which is rotated using insertion device 312 (or analternative insertion device) and which translates rotational motioninto linear motion of blades 322.

Referring now to FIGS. 49A-49C, another embodiment of a cervical fusioncage implant 330 is illustrated. In this embodiment, implant 330includes a body 332, which includes multiple contoured surfaces 333, twochannels 336 a, 336 b for receiving prongs of an insertion device, andtwo angled slots 338. Implant 330 also includes two anchoring plates 334a, 334 b (or “staples” and “anchoring blades”), which are configured tofit into angled slots 338, and which include sharp tips for anchoringinto vertebral bone. In some embodiments, each anchor plate 334 a, 334 bmay also include a feature 335 for engaging with a bone screw (notshown), after deployment. Anchoring plates 334 a, 334 b are incorporatedinto implant body 302 and are typically deployed by a drive mechanism,after body 302 is positioned between two vertebrae. Anchoring plates 334a, 334 b generally serve to provide resistance to vertical separation ofthe vertebral sections. In various embodiments, anchor plates 334 a, 334b may be straight or curved sharp-tipped blades with a thin profile. Inthe embodiment shown, anchor plates 334 a, 334 b are shaped as two thinprongs, for case of insertion into bone.

FIG. 49A is a perspective view of implant 330 completely assembled, FIG.49B is an exploded view of implant 330, and FIG. 49C illustratesinsertion of one anchor plate 334 a into one of the slots 338 of implantbody 302. Upon insertion into one of the angled slots 338, each anchorplate 334 a, 334 b extends away from the insertion tool, toward theposterior side of the vertebrae. The insertion tool uses an impact-baseddriving mechanism, rather than a screw drive.

Referring now to FIGS. 50A-50C, a portion of an insertion device 340 forinserting implant 330 is illustrated in side view. Referring first toFIG. 50A, insertion device 340 may include a distal portion 350, whichincludes a staple driver 342 (or “anchor plate driver”), a shaft 348, atrigger 344 and a spring 346. Staple driver 342 may be used to provideimpact force onto each anchor plate 334 a, 334 b, in sequence, toconvert axial motion into the appropriate angle to drive each anchorplate 334 a, 334 b into the bone. FIG. 50A shows insertion device 340 ina pre-deployment position.

FIG. 50B illustrates insertion device 340 with trigger 344 partiallyactuated, spring 346 compressed, and staple driver 342 retracted. FIG.50C illustrates insertion device 340 with trigger 344 fully actuated,spring 346 released, and staple driver 342 fired. This mechanism ofaction may be used to advance anchor plates 334 a, 334 b into slots 338on implant 330.

The foregoing merely illustrates various exemplary embodiments indetail. Various modifications and alterations to the describedembodiments may be made within the spirit and scope of the presentdisclosure. Thus, the particular embodiments shown and described are forpurposes of illustrations only and are not intended to limit the scopeof the present disclosure. References to details of particularembodiments are not intended to limit the scope of the disclosure. Thepresent invention extends beyond the specifically disclosed embodimentsto other alternative embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the present invention herein disclosed should not belimited by the particular disclosed embodiments described above, butshould be determined only by a fair reading of the claims that follow.

1-30. (canceled)
 31. A trial device for testing a size of a disc spacebetween two vertebrae and preparing opposing bone surfaces of the twovertebrae to accept a fusion cage implant, the device comprising: a bodycomprising a superior surface, an inferior surface, an anterior surface,an opening extending from the superior surface to the inferior surface,and at least one feature on or through the anterior surface for couplingthe body with an insertion device; at least one blade moveably disposedin the opening of the body, such that the at least one blade can bemoved in such a way as to extend at least one of superiorly above thesuperior surface of the body or inferiorly below the inferior surface ofthe body to cut vertebral bone of a least one of the two vertebrae; andan actuator coupling the at least one blade to the body in such a waythat actuating the actuator causes the blades to move and thus cut thevertebral bone.
 32. The device of claim 31, wherein the body has aconfiguration similar to that of an interbody fusion cage implant. 33.The device of claim 31, wherein the at least one blade comprisesmultiple rotating blades, and wherein the actuator rotates to rotate theblades.
 34. The device of claim 31, wherein the at least one bladecomprises multiple linear-travel blades, and wherein the actuatorcomprises a gear that moves the linear-travel blades up and down. 35.The device of claim 31, wherein the at least one feature comprises twochannels for accepting tow prongs of the insertion device.
 36. Thedevice of claim 31, further comprising the insertion device removablyattached to the anterior surface of the body.
 37. The device of claim36, wherein the insertion device comprises: a distal portion forcoupling with the body of the trial device; a proximal handle; a shaftextending from the distal portion to the handle; and a knob on thehandle for actuating the actuator to move the at least one blade.
 38. Atrial device for testing a size of a disc space between two vertebraeand preparing opposing bone surfaces of the two vertebrae to accept afusion cage implant, the device comprising: a body comprising a superiorsurface, an inferior surface, an anterior surface, an interior openingextending through the superior surface and the inferior surface, and atleast one feature on said body for coupling the body with an insertiondevice, said body being of size and configuration similar to that of aninterbody fusion cage implant; at least one cutting device rotatablydisposed in the opening of the body, such that the at least one cuttingdevice can be rotated in such a way as to extend at least one ofsuperiorly above the superior surface of the body or inferiorly belowthe inferior surface of the body to cut vertebral bone of at least oneof the two vertebrae; and an actuator coupled to the at least onecutting device such that actuating the actuator causes the at least onecutting device to rotate and thus cut said vertebral bone.
 39. Thedevice of claim 38, wherein the at least one cutting device comprisesmultiple rotating blades.
 40. The device of claim 39, wherein themultiple rotating blades are configured to rotate within body uponactuation of said actuator from a first position wherein said blades arefully contained within said body to a second position wherein at least aportion of said blades extends outside said superior surface and saidinferior surface of said body.